Sirius Satellite Radio and XM Satellite Radio are two companies currently providing subscription digital satellite radio services. Such services are referred to as S-DARS, for Satellite Digital Audio Radio Service, or more succinctly as satellite radio. In both the case of Sirius and XM, it is inherent in their design to simultaneously transmit signals to radio receivers from multiple satellites and a network of “terrestrial repeaters” (multiple ground-based transmitters, located for example in large cities, where tall buildings often block satellite reception). See for example, David H. Layer, “Digital Radio Takes to the Road,” IEEE Spectrum, July 2001, pages 40-46. Such satellite transmission, per se, is not the subject of the instant invention.
Subscription fees for service with no advertising need to be higher than subscription fees for service with advertising since the full cost of the service must be borne by the user when there is no advertising revenue. Initially, Sirius offered commercial-free music at a monthly subscription fee of $12.95 and XM offered partly commercial-free music at a monthly subscription fee of $9.95. Sirius' totally commercial-free music was a competitive advantage for many potential subscribers and, on Feb. 1, 2004, XM's music channels also became totally commercial-free. However, XM could not immediately raise its subscription fee without alienating much of its existing subscriber base and had to suffer a loss of revenue for over a year before it was able to raise its rates to match those of Sirius.
Terrestrial radio, particularly in the 88-108 MHz FM band, faces a similar problem as it converts to a digital format known as HD radio. If a network of stations goes commercial-free, it alienates subscribers who do not wish to pay a subscription fee. But, if the network maintains its current, commercial-supported approach, it loses to satellite radio the significant fraction of its listener base which prefers commercial-free radio.
The dilemma faced by XM and terrestrial radio can be solved by offering tiered subscription services, ranging from totally commercial-free to totally commercial-supported. Then each subscriber can choose the plan that best meets his or her needs.
A system for providing such a tiered subscription service can be easily, but inefficiently, accomplished by having two versions broadcast for each channel: one with commercials and one without. The version that contains commercials clearly also has less entertainment content, since some time is being used by the commercials. In the case of popular music, the content usurped by the commercials can be one or more entire songs since each song lasts approximately three minutes and commercial breaks typically last at least about that long.
The above-described two tier system, which transmits two versions of each channel, one with and one without commercials, has a major drawback in that it would halve the number of channels that the broadcaster could offer. Effectively, each channel has become two channels, one with commercials and one without.
The present invention allows a broadcaster to deliver two or more tiers of services over a single channel and charge subscribers different or no subscription fees, with fewer or no commercials being delivered to the highest tier subscribers. To accomplish this, the present invention uses memory located at the receiver to store commercials and has the broadcaster transmit receiver commands telling lower tiered subscribers' radios which content segments of the normal program are to be deleted and which commercials are to be inserted in their place.
The use of memory at a receiver is well known in the art. DirectTV, for example, offers a TiVo equipped satellite television receiver, which can store programs on a hard drive and play them back at a later time. In U.S. Pat. No. 6,785,656 “Method and apparatus for digital audio playback using local stored content” Patsiokas et al describe a similar system for use with satellite radio. Since TiVo and its competitors are called PVR's (Personal Video Recorders), Patsiokas' invention might be called a PAR (Personal Audio Recorder).
In U.S. Pat. No. 6,564,003 Marko et al describe another use of memory with satellite radio. Marko demodulates the bit stream from a broadcaster, such as XM Satellite Radio, and records it on a memory medium (e.g., a recordable CD) for later playback at a location that either cannot receive the satellite signal or does not need real time reception. As in Patsiokas, the selection of the recorded program to be played back is subscriber controlled.
In contrast to Patsiokas and Marko, the present invention has the broadcaster, not the subscriber, determine when to access stored content and which stored content is accessed. These determinations are done in a manner substantially different from the cited prior art and for a totally different purpose. Whereas Patsiokas and Marko used memory at the receiver to enhance the subscriber's listening experience, this aspect of the present invention uses such memory to allow tiered subscription services.
In US Patent Application 2004/0116070 “Method, system, and computer program product for providing multi-tiered broadcasting services,” filed Nov. 20, 2003, Fishman et al describe a tiered subscription system for use with satellite radio. The present invention gives the broadcaster greater control than Fishman, thereby providing a better experience for the subscriber and more effective exposure for the advertiser. For example, in the present invention, specific songs can be deleted to make room for ads, ads can be targeted to specific subscribers, ads are less likely to be lost in transmission, ads that are lost in transmission are replaced by similar ads, audit information is provided to the broadcaster and advertiser, and the radio receiver is more secure.
In U.S. Pat. No. 5,815,671 “Method and apparatus for encoding and storing audio/video information for subsequent predetermined retrieval,” issued Sep. 29, 1998, Morrison describes a system for customizing entertainment for individual subscribers which includes the possibility of offering commercial-free service to some subscribers and commercial-supported service to other subscribers. Unlike the present invention, Morrison's system is designed to work in non-real-time, utilizing stored program material, and is thus not usable with real-time broadcast systems such as satellite radio. Morrison's system is also designed to work with a totally new class of receivers and did not, as the present invention, have to allow pre-existing receivers to continue to function. The advantages of the present invention listed above relative to Fishman (specific songs can be deleted to make room for ads, ads can be targeted to specific subscribers, ads are less likely to be lost in transmission, ads that are lost in transmission are replaced by similar ads, audit information is provided to the broadcaster and advertiser, and the radio receiver is more secure) are also advantages over Morrison.
In U.S. Pat. No. 6,289,455 “Method and apparatus for preventing piracy of digital content” Kocher et al describe a secure CryptoFirewall which protects critical portions of memory so that cryptographic keys used by a cryptoprocessor are inaccessible to all other parts of the system. These keys are made inaccessible to avoid the danger of a pirate attempting to learn them, creating a CryptoFirewall in Kocher's terminology. This architecture prevents the frequent error in the implementation of cryptograpic systems of storing keys in normal read-write memory where the keys are potentially accessible to piracy. The thinking behind this frequent error is that keys need to be written when entered and read when used for encryption or decryption. While this is true, allowing keys to be read by parts of the system which have no need for them other than for piracy, is extremely dangerous. Kocher, however, makes no use of commercials or of tiered subscription services.
In U.S. Pat. No. 6,434,622 “Multicasting method and apparatus” Monteiro et al use multicasting over the Internet to target advertising based on user demographics.
In US Patent Application 2004/0083487 Collens et al describe a media distribution system which delivers content to a user in encrypted form and then delivers keys to unlock the content on a specific playback device.